Miller



vJ.`]:"'.1VIILLER. Spring Draft or Tug-ElinkI f|`\1e.1224,21`o.` Y Patented Feb. 3', Isso.

MPETFRS. PHoTo-LITHOGRAPMER. WASHINGTON. D, c:

vpresently appear.

A.UNITED STATES PATENT' OFFICE..

JOHN F. MILLER, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO DANIEL RISHEB, 0F SAME-PLACE.

SPRING DRAFT OR TUG LINK.

SPECIFICATION forming part of Letters Patent No. 224,210, dated February 3, 1880.

Application filed December 19, 1879.

To all whom ttmay concern,

Be it known that I, JOHN F. MILLER, of Pittsburg', county of Allegheny, State of Penn` sylvania, have invented or discovered a new and useful Improvement. in Spring' Draft or Tug Links and I do hereby declare the following to be a full, clear, concise, and exactf de scription thereof, reference. being had to the accom pan yin gdrawin gs, making a part of this specification, in whichlike lettersindicating like partsy Figure] illustrates, by a sectional elevation, my improved spring draft or tug link; Fig. 2 shows a transverse section of the same, taken in the line x a', Fig. 1. Fig. 3 also shows a transverse section, but taken in the line y y, Fig. l; and Fig. et is a perspective view of one part or member ofthe body of the link.

My present invention relates to spring draft or tuglinks, and more particularly to the construction and arrangement of the U-'shaped bars which form the body or barrel of the link. It isconstructed as follows: Four segmental bars, A A and B B, are arranged in such way that their rounded or convex outer faces form a barrel or cylinder, as seen in Fig. l. The two opposite bars A Aare connected at one end by a loop, A', of any desired form and size, except Vas hereinafter provided, and the opposite'ends of bars B B are connected by a similar loop, B'. The 'external width of this loop B should not be greater than the diameter of the barrel A B, for reasons which will Upset heads or collars a and b are made on the open ends of the bars A and B, which serve as shouldersA or bearings for a coiled spring, C, which encircles the barre] A B.

The inner faces of the bars A and B are made dat, with the two opposite faces arranged parallel. The edges of these bars next to their respective connected ends are cut away, as at c, leaving the bars along such cutaway parts equal in width togthe distance between the at inner faces of the two adjacent bars, while full edges c are left on the bars next to their open or unconnected' ends, the

length of which full edges is, by preference, equal to half the length of spring C when 'com-y pressed to the full extent desired. In putting passed between them into the loop B.

-tion in spring draft -links.

these parts together the spring G is first placed on the U- shaped bars- AA, Fig. 4, by compressing `their open end. Then, by making the loop A equal in thickness to the distance between' the inner faces of B B, it may be 55 A These bars B B are then pushed, the loop B being foremost, between the bars A A until the shoulders a and b bear against the ends ot' spring C and the twoloops A and B project 6o from the opposite ends of the device, as in will have edge-bearin gs against the flat inner faces of A A at c', as shown in Fig. 2, while along the full part of B it will have a reverse 7o relation, as in Fig. S--that is, a face-bearing against the edges of A A. I thus secure two edge and two face bearings for all and each of the bars. Suchi an arrangement greatly increases the strength and durability of the device, and prevents all possibility of the bearing-edges of the bars from becoming relatively displaced,'as has been found to he the case Where the hars have either a miteredge bearing along their entire length, or, on 8o the other hand, where they have face-bearings only.

By properly arranging the relative lengths of cu t-away and full edges c and c', I secure a distance between shoulders c and e', made by 85 cutting away the edges c, as described, equal vto thedesired range of action of the spring; then, as the bars A and B have movement upon each other, caused by strain upon the two ends, the shoulders e ande come against 9o each other, and thus prevent further' compression of the spring. I thus prevent danger of breaking or injuring the spring by too great compression, which is an important considera- VAs before described, I. prefer te secure this distance betweenV stops e and e', or the desired range of spring action, by making the several edges c equal in length to half the length of the com-. pressed spring; but this preference is based.xoo

principally on convenience in construction7 as the acting distance between stops e and e may be secured by making some of the edges c shorter than mentioned, and others, which act with or against them, proportionately longer.

By the construction described I secure a spring draft or tug link superior both in durability and simplicity.

It will be observed that the maximum strain on the shoulders a and b is in all cases measured by the carrying-power or elasticity of the spring, and that anyA excess of strain is borne by the stops e and e. Danger of breaking the shoulders a and b is thus obviated.

I claim herein as my invention- 1. In a spring draft or tug link, the combination of the U-shaped segmental bars A and B, such bars having cut-away edges c through l In testimony whereof I have hereunto set 3o my hand.

JOHN F. MILLER.

Witnesses:

R. H. WHITTLEsEY, C. L. PARKER. 

